Understanding the causes of high blood pressure

Her work in the BHF Centre of Research Excellence and the clinic helps BHF Professor Rhian Touyz investigate the causes of high blood pressure. She talks to Sarah Kidner.

BHF Professor Rhian Touyz has “a vision” to better understand how damage and aging of the vascular system causes cardiovascular disease and, in particular, hypertension. The vascular system includes not only the main arteries feeding the heart and brain, but also a network of small arteries that supply the eyes, kidneys and every other major organ.

Vascular damage and hypertension occur silently and are a major cause of devastating common chronic diseases such as heart attack, stroke, renal failure and dementia.

Professor Touyz moved more than 3,500 miles from Canada to the University of Glasgow two and a half years ago to follow her vision. “The university invited me to take over the directorship of the Institute for Cardiovascular Medical Sciences. I saw this as a fantastic leadership and research opportunity,” says Professor Touyz, formerly Canada Research Chair in Hypertension.

Hypertension is the biggest contributor to the global burden of disease

The university has since become a BHF Centre of Research Excellence, and under Professor Touyz’s leadership, it is working hard to discover possible causes of vascular dysfunction (damage to the blood vessels), which contributes to hypertension and many associated cardiovascular diseases. “I have always been very interested in the biology of vessels in health and disease, and that’s what the Centre of Excellence allows us to study in its broadest sense,” she says.

Professor Touyz’s specific focus is on hypertension, which affects about 16 million people in the UK and is a major risk factor for cardiovascular disease. “Hypertension is the biggest contributor to the global burden of disease,” she says. “There is a need to better understand the mechanisms of the disease and to develop new therapies.”

Molecular mechanisms

Professor Touyz and her team believe that one of the mechanisms behind vascular damage in hypertension could be a certain type of enzyme.

“There are many different proteins that may contribute to abnormal function of the cells that make up the blood vessels. One of these proteins is an enzyme called Nox5. We think that in hypertension, the regulation of Nox5 is abnormal and it produces too many oxidants [free radicals], which damage the blood vessels,” she explains. “It’s like a hosepipe, where the pipe becomes constricted and the diameter is reduced. The same thing happens to blood vessels as they become inflamed and damaged. If the small vessels become narrowed and constricted, the pressure inside them increases.”

By better understanding how Nox5 works, researchers might be able to develop therapies that target or ‘inhibit’ it so that normal function of the protein can be regained. “There are a number of pharmaceutical companies that are very interested in developing inhibitors that will target Nox5. We believe that this may deliver new therapies that can better treat vascular damage and hypertension,” says Professor Touyz. “Hopefully within the next five years, we should have more definitive outcomes to take the field further and use those drugs clinically.”

The bigger picture

Professor Touyz also has a broader interest in patients with chronic health conditions, something she is aware of through her work treating patients with hypertension at the Western Infirmary, Glasgow. “Unfortunately, Glasgow has a very high population of patients with cardiovascular disease. [These] patients often have very severe and complex hypertension and multiple co-morbidities [other diseases]. I particularly enjoy working in the clinic as a physician and to appreciate what patients have to deal with,” says Professor Touyz.

“Wherever possible, the basic research that I do in the laboratory is done with tissues or cells from patients rather than from animal models. This allows us to get better insights into mechanisms of cardiovascular disease in humans. As a researcher, I would never stop seeing patients; I feel privileged to be able to see patients in the clinic and then to perform experiments in the laboratory to address clinically relevant questions.”

Mentoring trainee researchers

As well as directing the Institute of Cardiovascular and Medical Sciences and leading the BHF Excellence Award, Professor Touyz oversees her own research group. She takes pride in running a trainee-oriented lab, with many national and international students and fellows. To date, she has trained more than 40 graduate and post-graduate students and currently has 20 students, from senior post-doctorate students to master’s students in the lab.

I am honoured and proud to be here and to have had incredible support from the BHF

“I am fortunate to have had fantastic mentors and to have been given wonderful opportunities so my own career could grow. I have always wanted to share that and pass it on,” says Professor Touyz.

She still keeps in touch with a number of former students, and many have gone on to have successful careers in their own right worldwide. “Two of my students have developed their own independent careers in Australia, another is in Spain and two are in Canada. Others in Brazil, Germany and Argentina are now full professors running active and successful labs,” she says.

As for Professor Touyz, she feels privileged to be working in Glasgow. “I am honoured and proud to be here and to have had incredible support from the BHF.”

Concerned about your blood pressure?

High blood pressure means that your blood pressure is constantly higher than the recommended level. High blood pressure increases your chance of having heart disease or stroke. High blood pressure isn’t usually something that you can feel or notice.

If you’re over 40 and not already diagnosed with coronary heart disease, diabetes, kidney disease, or had a stroke, you’re entitled to a free health check at your GP surgery.

If you haven’t had it, you can ask for one – there’s no charge for an NHS health check. Lifestyle modifications can help to reduce your blood pressure.

Centres of Research Excellence

Total funding to date awarded by the BHF and areas of special interest

£11.9m Imperial College: World-leading stem cell researcher BHF Professor Michael Schneider and his team hope to come up with ways to reverse the damage caused by heart failure. Read about the work of an Imperial PhD student in this field.

£15m King’s College London: This centre is making great strides in understanding the structure of the heart at a molecular level. One of our newest BHF Professors, Kinya Otsu from Japan, is researching new treatments for heart failure.

£3m University of Cambridge: BHF Professor Nick Morrell and his team are using innovative research approaches to find ways to prevent heart attacks.

£3m University of Glasgow: The funding will allow Glasgow scientists to investigate blood vessel damage that is caused by chronic conditions such as obesity and diabetes, as our feature above explains.

£14.4m University of Oxford: World-leading regenerative medicine specialists at Oxford, like Professor Hugh Watkins (pictured), are coming up with ways to repair damaged hearts.

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